Updating Firefox

In my testing of the TA's example site, I kept getting errors with the rating system. Every time I clicked on a star, the browser would display an error message. After installing firebug, I noticed that the javascript was posting a rating of "Infinity". I was a little confused about that and began reading over the source that submits ratings. For some reason I couldn't set any breakpoints in firebug. So I then tried it on a different computer. For some strange reason it worked fine. I then realized that the machine I'd been using (my wife's laptop; mine died years ago) had an old version of firefox, whereas the other machine was up to date. After upgrading my wife's firefox installation everything worked out perfectly. Lesson: upgrade and update.